<div class="refentry" lang="en" xml:lang="en"><a id="glGetBufferSubData"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glGetBufferSubData — returns a subset of a buffer object's data store</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table><tr><td><code class="funcdef">void <b class="fsfunc">glGetBufferSubData</b>(</code></td><td>GLenum  </td><td><var class="pdparam">target</var>, </td></tr><tr><td> </td><td>GLintptr  </td><td><var class="pdparam">offset</var>, </td></tr><tr><td> </td><td>GLsizeiptr  </td><td><var class="pdparam">size</var>, </td></tr><tr><td> </td><td>GLvoid *  </td><td><var class="pdparam">data</var><code>)</code>;</td></tr></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>target</code></em></span></dt><dd><p>
                    Specifies the target buffer object.
                    The symbolic constant must be <code class="constant">GL_ARRAY_BUFFER</code>,
                    <code class="constant">GL_COPY_READ_BUFFER</code>,
                    <code class="constant">GL_COPY_WRITE_BUFFER</code>,
                    <code class="constant">GL_ELEMENT_ARRAY_BUFFER</code>,
                    <code class="constant">GL_PIXEL_PACK_BUFFER</code>,
                    <code class="constant">GL_PIXEL_UNPACK_BUFFER</code>,
                    <code class="constant">GL_TEXTURE_BUFFER</code>,
                    <code class="constant">GL_TRANSFORM_FEEDBACK_BUFFER</code>, or
                    <code class="constant">GL_UNIFORM_BUFFER</code>.
                </p></dd><dt><span class="term"><em class="parameter"><code>offset</code></em></span></dt><dd><p>
                    Specifies the offset into the buffer object's data store from which data will be returned,
                    measured in bytes.
                </p></dd><dt><span class="term"><em class="parameter"><code>size</code></em></span></dt><dd><p>
                    Specifies the size in bytes of the data store region being returned.
                </p></dd><dt><span class="term"><em class="parameter"><code>data</code></em></span></dt><dd><p>
                    Specifies a pointer to the location where buffer object data is returned.
                </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
            <code class="function">glGetBufferSubData</code> returns some or all of the data from the buffer object currently
            bound to <em class="parameter"><code>target</code></em>. Data starting at byte offset <em class="parameter"><code>offset</code></em> and
            extending for <em class="parameter"><code>size</code></em> bytes is copied from the data store to the memory pointed to by
            <em class="parameter"><code>data</code></em>. An error is thrown if the buffer object is currently mapped, or if
            <em class="parameter"><code>offset</code></em> and <em class="parameter"><code>size</code></em> together define a range beyond the bounds
            of the buffer object's data store.
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
            If an error is generated,
            no change is made to the contents of <em class="parameter"><code>data</code></em>.
        </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
            <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>target</code></em> is not
            <code class="constant">GL_ARRAY_BUFFER</code>, <code class="constant">GL_ELEMENT_ARRAY_BUFFER</code>,
            <code class="constant">GL_PIXEL_PACK_BUFFER</code>, or <code class="constant">GL_PIXEL_UNPACK_BUFFER</code>.
        </p><p>
            <code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>offset</code></em> or
            <em class="parameter"><code>size</code></em> is negative, or if together they define a region of memory
            that extends beyond the buffer object's allocated data store.
        </p><p>
            <code class="constant">GL_INVALID_OPERATION</code> is generated if the reserved buffer object name 0 is bound to <em class="parameter"><code>target</code></em>.
        </p><p>
            <code class="constant">GL_INVALID_OPERATION</code> is generated if the buffer object being queried is mapped.
        </p></div>
        {$pipelinestall}{$examples}
        <div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
            <a href="glBindBuffer"><span class="citerefentry"><span class="refentrytitle">glBindBuffer</span></span></a>,
            <a href="glBufferData"><span class="citerefentry"><span class="refentrytitle">glBufferData</span></span></a>,
            <a href="glBufferSubData"><span class="citerefentry"><span class="refentrytitle">glBufferSubData</span></span></a>,
            <a href="glMapBuffer"><span class="citerefentry"><span class="refentrytitle">glMapBuffer</span></span></a>,
            <a href="glUnmapBuffer"><span class="citerefentry"><span class="refentrytitle">glUnmapBuffer</span></span></a>
        </p></div><div class="refsect1" lang="en" xml:lang="en"><div id="Copyright"><h2>Copyright</h2><p>
            Copyright © 2005 Addison-Wesley.
            This material may be distributed subject to the terms and conditions set forth in
            the Open Publication License, v 1.0, 8 June 1999.
            <a href="https://opencontent.org/openpub/" target="_top">https://opencontent.org/openpub/</a>.
        </p></div></div></div>
